Background: The anti-inflammatory and immune enhancing effects of coenzyme Q10 (CoQ10) and hyaluronic acid are well established in medical literature. The present study was undertaken to evaluate their role in chronic periodontitis. Materials and Methods: One hundred twenty sites in 24 patients with clinically confirmed periodontitis were included in the study. A split-mouth design was used for intrasulcular application of CoQ10as adjunct to scaling and root planing (SRP), 0.8% hyaluronic acid as adjunct to SRP and SRP alone. Clinical parameters such as plaque index (PI), gingival color change index (GCCI), Eastman interdental bleeding index (EIBI), pocket depth (PD), and clinical attachment level (CAL) were recorded. All the clinical parameters PI, EIBI, GCCI, PD, and CAL were recorded at baseline before SRP. Only PI, EIBI, and GCCI were recorded at 1st and 2nd week. Twenty-one days post 2nd week, i.e., 6th week all the clinical parameters were recorded again. Results: Intragroup analysis of all the clinical parameters showed clinical significant results between baseline and 6th week. However, on intergroup analysis, the results were not significant. Conclusion: The local application of CoQ10and hyaluronic acid gel in conjunction with SRP may have a beneficial effect on periodontal health in patients with chronic periodontitis.

Periodontitis is an inflammatory disease of the periodontium which elicits an immune response resulting in loss of supporting structures of the teeth. It is independent of various ethnic groups and may be present in children to the elderly. The usual modes of treatment for periodontitis include informing the patient about the disease, oral hygiene instructions, scaling and root planing (SRP), and if indicated periodontal surgery and in some cases administration of systemic and local chemotherapeutic agents. Sometimes a combination of mechanical and chemical treatment provides good recovery. However, the final success rate of treatment depends on the status and maintenance of oral hygiene.[1]

It is well known that mechanical therapy alone provides an excellent clinical response in most patients but in certain patients increasing pocket depth (PD) and complicating anatomic factors limit the effectiveness of SRP. Many better-known antimicrobials and biomaterials have been used in the past, but in recent times certain less well-known compounds have significantly shown the potential to augment results of periodontal therapy. Two of such molecules are hyaluronic acid and coenzyme Q10 (CoQ10).[2]

Hyaluronic acid is a high molecular weight polysaccharide (glycosaminoglycan) and plays a vital role in the functioning of the extracellular matrix, including those of mineralized and nonmineralized periodontal tissues. It is a critical component of the extracellular matrix and contributes significantly to tissue hydrodynamics, cell migration, and proliferation. The use of hyaluronic acid in the treatment of inflammatory process has been well established in medical areas to treat radioepithelitis, osteoarthritis of the knee, rheumatoid arthritis, cataract surgery, etc., Its wide use in the treatment of inflammatory conditions of the knee and temporomandibular joint has led to its application in the field of periodontics.[3]

Hyaluronate has shown anti-inflammatory, anti-edematous, and antibacterial effects for the treatment of gingivitis and periodontitis.[4] It has also been studied as a metabolite or diagnostic marker of inflammation in the gingival crevicular fluid as well as a significant factor in growth, development, and repair of tissues.[3] Its free radical scavenging and protein exclusion properties offer protection to cells and extracellular matrix.[5]

CoQ10 is a compound found naturally in mitochondria and plays an important role in electron transport chain process. However, its role as an antioxidant has been well established, so it is essential for the health of all tissues and organs. It is also helpful in the regeneration of other antioxidants, stimulation of cell growth, and inhibition of cell death.[6]

Although CoQ10 is synthesized in the body, situations may arise in which the body's synthetic capacity is insufficient to meet requirements for its production. This situation is seen in tissues that are metabolically active such as heart, immune system, gingiva, gastric mucosa, and can lead to dysfunctioning of these tissues.[7]

CoQ10 deficiency is frequently associated with periodontal diseases and its administration to periodontal tissues may control advanced periodontitis.

It prevents the generation of free radicals. Topical administration to the gingiva as a sole treatment may decrease GCF flow and probing depths and improve clinical gingival attachment. CoQ10 supplementation has been beneficial for patients at risk of periodontal diseases especially diabetics.[8]

Various investigators have tested these two molecules in chronic periodontitis. The results have been quite controversial according to some studies showing statistically significant improved results while others showing no additional benefit of these molecules. This might be due to a difference in frequency and method of administration of the drugs.

An attempt has been made through this study to evaluate the efficacy of administrating hyaluronic acid and CoQ10 as an adjunct to SRP and find out if there is any beneficial role of both the molecules in treating chronic periodontitis.

Materials and Methods

Exactly 120 sites in 24 patients were clinically confirmed for chronic periodontitis. The subjects for this randomized, controlled study were selected from the outpatient Department of Periodontics, Himachal Institute of Dental Sciences College and Hospital, Paonta Sahib (Himachal Pradesh).

Patients were selected for the study according to the following criteria: Inclusion criteria for the study were patients between age group 25 and 55 years, patients in good systemic health; chronic generalized periodontitis with ≥5 mm periodontal pocket, adequate attached gingiva, the diseased sites should bleed on probing, and patients who were able to follow verbal or written oral hygiene instructions. The exclusion criteria included patients having a history of oral prophylaxis in past 6 months, patients taking antibiotics in the past 3 months, patients with a history of systemic disease (cardiovascular diseases, diabetes, blood disorders, hepatitis, and renal diseases), and pregnant and lactating mothers.

CoQ10 (Perio Q10 gel Manufactured by Perio Q Inc., Manchester, USA) [Figure 1] or ubiquinone is essentially a vitamin or vitamin-like substance. It is supplied as a pack of gel, contains a mixture of CoQ10 and vegetable glycerine base in a ratio of 1:9. The gel should preferably be used within 48 months from the date of manufacture and stored in a dry area away from sources of light and heat. CoQ10 is found in small amounts in a wide variety of foods and is synthesized in all tissues.[6] It is known as coenzyme because of its unique ability to participate in chemical reactions but remain at steady state levels in the cell and plays a central role in energy metabolism.[9]

Hyaluronic acid (Gengigel ®, Ricerfarma, Milan, Italy) [Figure 1] is a mucopolysaccharide, which is present naturally in all living organisms. It is found primarily in the extracellular matrix but has been found intracellularly. Its functions include cellular and extracellular interactions, interactions with growth factors and regulation of the osmotic pressure, and tissue lubrication. All these functions help in maintaining the structural and homeostatic integrity of the tissues.

The samples were divided using simple randomization technique of rolling the dice. The patients were divided into three groups' viz., A, B, and C. If the outcome was numbered 1 or 2, the patient was allotted Group A, if the outcome was 3 or 4 then the patient was allotted Group B and if the outcome was 5 or 6 then the patient was treated in Group C.

Blinding was also ensured as one investigator administered the drugs during subsequent visits while evaluation of results was done by a separate investigator who was unaware of the intervention given to the test groups.

Cast models of the selected patients were poured. Occlusal stents were made to compare the pre- and post-surgical measurements. A groove on occlusal stents was made corresponding to the area of highest PD with a tapering low-speed bur. These grooves help in maintaining the same position and angulations during measurement recording. Using the groove as a guide, the periodontal probe was inserted into the pocket and clinical measurements were obtained at the baseline and after 5 weeks, i.e., 6 weeks [Figure 2] and [Figure 3].

Experimental sites received Perio Q ™ gel in Group A, Gengigel ® in Group B, and no drug was placed in Group C following SRP. The gels were placed in the pockets using a wide gauge needle which was inserted till the base of the pocket. It was made sure that the gel slightly overflowed during placement from the pocket. All the three experimental sites were covered by coe pack.

The following parameters were assessed in the study:

PI - At baseline, 1st, 2nd, and 6th week

EIBI - At baseline, 1st, 2nd, and 6th week

GCCI - At baseline, 1st, 2nd, and 6th week

PD - At baseline and 6th week

CAL - At baseline and 6th week.

Statistical analysis

Mean values and standard deviation were calculated for different parameters in Group A, B, and C at baseline, 1st, 2nd, and 6th week. Kruskal–Wallis test was applied to determine if there was any significant difference between the parameters of the three groups. Wilcoxon signed test was performed for same parameters at different time intervals. Chi-square test was used to calculate the test of significance for Eastman interdental bleeding index as it involved qualitative data, i.e., presence or absence of bleeding from the involved sites.

Results

A total of 24 patients (120 sites) participated in the study. Of these, forty sites were treated by SRP + Perio Q ™ Gel, forty sites with SRP + Gengigel ®, and the remaining forty sites by SRP alone. The following observations were made for different parameters in the three test groups.

Plaque index

At baseline in Group A, B, and C the mean PI was 1.35 ± 0.53, 1.43 ± 0.64, and 1.35 ± 0.62, respectively [Table 1] and [Figure 4]. At 1st week in Group A, B, and C the mean PI was 0.70 ± 0.52, 0.78 ± 0.53, and 0.85 ± 0.48, respectively (P < 0.05) [Table 2] and [Figure 5], at 2nd week in Group A, B, and C the mean PI was 0.82 ± 0.59, 0.82 ± 0.59, and 0.87 ± 0.65, respectively (P < 0.05), [Table 3] and [Figure 6] and at 6th week in Group A, B, and C the mean PI was 0.72 ± 0.60, 0.92 ± 0.57, and 0.82 ± 0.75(P <.05) [Table 4] and [Figure 7], respectively. On intragroup comparison, the results were statistically significant between baseline and 6th week in all the three groups [Table 5],[Table 6],[Table 7] and [Figure 8],[Figure 9],[Figure 10]. However, on intergroup comparison, no significant difference was noted at different time intervals.

At baseline, the percentage of EIBI in all the three groups was 100% [Table 1] and [Figure 4]. This reduced to 22.5% in CoQ10 group, to 35% in HA group, and to 32.5% in control group at 1st week [Table 2] and [Figure 5]. At 2nd week in CoQ10 group, only 17.5% of cases showed positive bleeding, while in HA group 22.5% showed positive bleeding and in control group 35% of cases showed positive bleeding [Table 3] and [Figure 6]. At 6th week in CoQ10 and HA group only 12.5% of patients were positive for bleeding while in control group 20% cases reported positive [Table 4] and [Figure 7]. These results were statistically significant when compared to baseline [Table 5],[Table 6],[Table 7] and [Figure 8],[Figure 9],[Figure 10]. On intergroup comparison, the results showed lesser values in both the test sites as compared to control group; however, these results were statistically not significant.

Periodontal pocket depth

Evaluating the PD at baseline shows the mean PD in Group A, B, and C as 5.53 ± 0.59, 5.80 ± 0.79, and 5.60 ± 0.87 [Table 1] and [Figure 4]. Following 6th week, the values of PD were as 3.20 ± 0.69, 3.52 ± 0.85, and 3.37 ± 1.00 [Table 4] and [Figure 7]. All these values were clinically significant from the baseline [Table 5],[Table 6],[Table 7] and [Figure 8],[Figure 9],[Figure 10]. However, no adjunctive beneficial effects of CoQ10 and HA was observed at 6th week in comparison to SRP group.

Clinical attachment level

The relative CAL between Group A, B, and C at baseline shows mean of CAL as 4.53 ± 1.26, 4.83 ± 1.24, and 4.50 ± 1.01 [Table 1] and [Figure 4]. The values at 6th week were 2.87 ± 1.09, 3.15 ± 1.37, and 2.75 ± 1.40 [Table 4] and [Figure 7]. On intragroup comparison, statistically significant difference was observed in all the groups between baseline and 6th week [Table 5],[Table 6],[Table 7] and [Figure 8],[Figure 9],[Figure 10]. On intergroup comparison, no statistically significant difference was found in between the three groups.

Discussion

Periodontal diseases are considered infections of the periodontium because of bacterial etiology, an immune response, and tissue destruction. The inflammatory and immune responses to the bacteria and viruses that colonize the periodontal and associated tissues involve the systemic circulation and ultimately the peripheral system of the body. This creates a complex bidirectional series of host-microbial interaction involving cellular and humoral factors and networks of cytokines, chemokines, and growth factors. The majority of periodontal tissue destruction is caused by an inappropriate host response to periopathogens and their product which includes overproduction of free radicals and reactive oxygen species, matrix metalloproteinases during the inflammatory process causing collagen and periodontal cell breakdown.[7]

Immunomodulators like CoQ10 has been beneficial in many chronic diseases such as congestive heart failure, diabetes, hypertension, COPD, and compromised immune states,[13] whereas hyaluronic acid has been beneficial in diseases such as rheumatoid arthritis, osteoarthritis, and radioepithelitis.[4] The pharmacology of these drugs suggested that they may show positive treatment outcomes in periodontitis.

The present study was carried with the objective to carry out a comparative evaluation of CoQ10-based gel and 0.8% hyaluronic acid gel in the treatment of chronic periodontitis.

The results obtained in the present study indicate that both the immunomodulators, i.e., CoQ10 and hyaluronic acid markedly improve the benefits of SRP and are helpful in treating gingivitis. The clinical parameters, i.e., PI, GCCI, EIBI, PD, and CAL showed a statistically significant difference in results between baseline and 6th week in the three test groups. On comparison, it has been observed that CoQ10 shows superior improvement in gingival parameters as compared to hyaluronic acid and control group though the results were statistically nonsignificant. This can be due to immune enhancing effects of CoQ10.[9] As it plays crucial role in the generation of ATP and cellular respiration which helps in regeneration of cells, it acts as a scavenger for free radicals and reactive oxygen species, regenerates other antioxidants, and inhibits cell death. Finally, it has been known to mediate NFkB1-dependent pro-inflammatory cytokine tumor necrosis factor-alpha (TNF-α). These all effects contribute to resolve inflammation and promote wound healing.[14] On the other hand, hyaluronic acid being anti-edematous and acts as anti-inflammatory by draining prostaglandins, metalloproteinases, and other bioactive molecules. The significant improvement in the bleeding index can be addressed to mechanical debridement and properties of CoQ10 gel acting as anti-inflammatory and antioxidant which suppresses periodontal inflammation. The effect of CoQ10 on the NFkB1-dependent pro-inflammatory cytokine TNF-α was studied and was suggested that CoQ10 exerts anti-inflammatory properties via NFκB1-dependent gene expression. Aforementioned is a common pathway for periodontal inflammation, suggesting that this could be the possible mechanism for gingival inflammation 14 besides being scavenger for free radicals and reactive oxygen species.

Hyaluronic acid is known to enhance formation of extracellular connective tissue matrix, promoting wound healing, facilitating cell migration, and differentiation during tissue formation and repair leading to noninflamed and healthy periodontal tissue that is less susceptible to bleeding.[2] More recently, hyaluronic acid has been shown to be the main ligand of CD44 receptor involved in the initial binding of leukocytes to endothelial cells activated by the inflammatory process. This same receptor is involved in the interaction between gingival fibroblasts and T, B lymphocytes and can speed up the gingival immune response.[15] These findings suggest that both the test drugs are capable of treating gingivitis.

In patients with periodontitis, no major additional advantage was seen when compared with the control group in CoQ10 group which was in agreement with an earlier study done by Hans et al.[6] Similar findings were observed in hyaluronic acid group and were in accordance with the study done by Xu et al.[16] and Gontiya and Galgali.[2] In CoQ10 group, the nonsignificant results may be due unfavorable thixotropic properties of gel, unknown substantivity, and unknown bioavailability of the gel and as it was neither a sustained release nor a controlled release formulation, it may have had a short washout period than that desired for optimal results. In the hyaluronic acid group, intergroup nonsignificant results may be due to no antibacterial effect of HA although it has shown a bacteriostatic effect on aggregatibacter actinomycetemcomitans and Porphyromonas gingivalis n vitro, but periodontal environment is much more complex in vivo than an in vitro model can mimic.[16] The other reason could be that the gel was placed with the help of a syringe and it was uncertain that the gel reached the base of the pocket. HA gel is also not yet known to bind and penetrate the periodontal tissues, whereas it has been shown to be bioadhesive and retentive in nasal mucosa and ocular tissue respectively.[2]

However, other studies have shown statistically significant results in both the test groups. This difference can be due to differences in treatment protocols, observation intervals, disease severity, and measurements.

Conclusion

CoQ10 and hyaluronic acid when used as an adjunct to SRP, both proved to be effective in treating chronic periodontitis. The gingival parameters (EIBI) were better in both the test drugs as compared to SRP, but the results were nonsignificant. However, no additional benefit over SRP was seen in PD and CAL. Thus, further studies are encouraged to establish the role of the tested immunomodulators in periodontitis.